Rotary pump



Sept. 1I, 1928.

s. HgNDs ROTARY PUMP 5A sheets-sheet 1 Original Filed May 26, 1924 Sept. 11, A'1928'. 15684274 S. HNDS ROTARY uMP Original Filed May 26, 1924 3 Sheets-Sheet 2 Sept. l1, 1928. 1,684,274

- s. HlNDs v ROTARY PUMP Patented Sept. 1l, 1928.

UNITEDv STATES l i 1,584,274 PATENT, OFFICE.

SHERWOOD Hines, OP sT, LOUIS, MISSOURI, AssIeNOR To ST. LOUIS PUMP ar EQUIP- MENT COMPANY, OP ST. LOUIS, MISSOURI, 'A CORPORATION OP MISSOURI.

ROTARY PUMP.

Application led May 26,1924, Serial No. 715,849. Renewed February 11, 1928.

rl`his invention relates to pumps, and with regard to certainfmore Specic features, to positive-acting rotary pumps of the ungeared type, suitable for pumping either liquids o-r gases.

Among the several object-s Volf the invention lmay be noted the provision of low relative velocities between points in Contact at the sealing juncture between the vintake and dis- Y charge sides of the pump, and the provision of means for decreasing to a minimum Objectionable clearance volume. Other objects will bein part obvious and in part pointed out hereinafter.

The invention accordingly comprises the' features of construction, elements and. combinat-ions oit elements, and arrangements oi arts which are eXem liiied in the construc-' tion hereinafter described and the scope ot the application of which will be indicated in the following claims. v l

In the accompanying drawings, in which is shown one of various vpossible embodiments et this i nvention; y

F 1 is a side elevation of the pump with one side platcrcmoved, being substantially a vertical transverse section on the line 1-1 of Fia. 7

Fig. 2 is a similar view, showing other positions of the movable parts;

Fic'. is a vertical sectionon the line 3-8' of lli 7, showing` the parts at the beginning ot di-ifcharge and intake Operations; l

l? i 4. is a horizontal section on the line Lim@ ct Fi 3;

.g ha 5 is a. perspective Ot an oscillating abutment: f I

charge check valve; and

Fic'. i is a horizontal section on the line 7 7 of Fig. 1, on a. reduced scale.

Smilar referencecharacters indicate cor? wending part-s tl'iroughout the several` vie vs ot thc dra\\:ings. terring now more particularly 'to Figs. ,1' the. drawings, there is shown 'a casing 1 sing six chambers disposed as follows: ke chamber or passage 3, forwardly g. Gis a perspective of an oscillating dis chambers 13 and 15 are not entirely separated y 'from one another; because the parting wall Q1 (Figs.` 3 and 4)', separat-ing the Vpumping `chambers 9 and 111, does not extend to the top of the pump. The suction inlet 19 to the pump is located forwardly.

The two pumping chambers 9 and 11 and their pumping linkages, to be rdescribed later, are ma de in duplicate, said lpumping linkages, however, being mounted oppositely to one another. rllhepumping cycle is 360 degrees. This arrange-nient decreases vibration.k

' T he number of pumping' chambers can 'be increased byjviroperly phasingtheir pumping linkages. As the Operations of one chamber ty ,ical ot all, only the chamber 9 and its linkage will be described in detail.

The 'pumping chamber 9 comprises an incomplete'cylinder 23 bored from the side of the casing 1. One cylinder end is formed by the'parting wall 21 and the other by a cover plate such as the plate 29 in Fig. d., Thewall 2i and cover plate'are both machined flat on theirinncr side. A drive shaft 27`isy mounted horizontally along the center line of the cylinde: 28 and passes through the parting' wall 21 and the cover plate within suitablebearings. lVithin the chamber 9, the drive shaftl 27 carries upon it an eccentric 529. The dis-A centriclto the center-line of ,the'drive shaft 27 is less than thevradius oit the cylinder by an an'iount slightly greater than thc thickness el the eccentric strap 31 placed around the eccentric 29. y

lllithin the upperlett-hand quadrant ot the eccentric' strap 3l is laterally imbedded and secured a key 33, the key 33 also being imbedded in and secured to a laterally dis-r posed shat't 95 oscillating in' the sealing' block 39 of the oscillating abutment 37T. The eccentric' strap 31, the vkey 33 and the .oscillating shaft 35 form a rigid oscillating'connecting link '3G between the eccentric 29 and the oscillating abutment 37., The oscillating` abutment 37 (Fig. comprises an arm i3 and the sealing block 39 in whichoscillates rthe linkBG on the shalt 35, (Fig.'1-'3). The sealing block 39 vand link 36 serve Jco-separate the discharge lfrom. the intake `side of the pump. 'The sealing block 39 oscillates substantially upwardly and downwardly about the laterally disposed roclcshatt 41, andthe block has its 4forward surface 45 machined cylindrically with the center-line of the rockshaft as center. Said surface engages a similarly machined surface 37 on'the wall 49 which Vdivides the valve chambers 13 and 15 from theintake chamber 3. f The abutment 37 is of bronze and the pump casing isof cast iron. This makes the originally tight seal between the engaging surfaces 45 and 47 of a permanent character. .Furthermorc, the

`pumped fluid forms the actual seal between the surfaces 45 and 47. In the case of aliquid e this is due to capillaryaction and in the' case ofgases to stagnation. j

The discharge valve 5l (Fig. 6) is rotatably mounted on the rock-shaft 41. This valve comprises two arms 53 in which are bored holesV 55 for mounting on the rock-shaft 41 (Fig. 6). `The to arms are joined at their forward ends by the substantially vertical valve gate 57, whose inner cylindrical surface 59 is machined to conform to the adjacent surface 61 of the pump housing. Thesesurfaces 59 and 61 are machined with the rock-shaft' centerline as center.

45 and 47 of the sealing block and forward wall. The valve is of bronze. i The lowersurface 63 of the valve gate is so machined that it is cylindrical with respect to the center line of the drive shaft as center when the gate is in the position shown inFig. 3.V This surface 63 thus forms part of the incomplete cylinder 23 when the valve is raised to its fullest extent (Figs. 1 and 3). `The gate 57 is made wider than the valve as a whole, in order that :it may be economically machined for `endfitting between the wall 21 and the end plate. This con-struction, furthermore, results in relatively little frictional resistance of the valve for agive'n tightness of joint.

The exhaust valve 51V as a whole straddles the arm 43 of` the abutment 37 on the rockshaft- 41. On one of its arms 53 is disposed the bell-crank 65, said bell crank v(i5 having formed at upper remote end a lug 67. Vhen the valve'rises, thisglug 67 comes against an adjustable stop G9 screwed into the pump 'case 1. In the present embodiment the stop 69 comprises an adjustable bolt and a locking nut. j

Formed on the under side of one of the arms 53 is the lug stop 71 (Figs. 1-3 and 6) They are sealed in the same manner as the above descrlbed surfaces ing glands around the drive shaft 27 unnecessary, as no fluid reaches theshaft. Likewise no Huid can reach the surface between the eccentric 29 and its strap 31 to cut a lubricant there. Nor can the lubricant leak out. Consequently at the surface of highest rubbing-- speed, lubrication can be carried on under favorable conditions. All other rubbing surfaces o n the pump are. in contact with the pumped fluid but have low relative velocities. This is particularly advantageous where thin,

volatile fluids are being pumped. The eccen-l tric strap 31 is made of cast-iron or bronze, while its eccentricV is made of a dissimilar metal in order to insure long wear at the lbearing surface. A

Referring now to Figs. 1-3, the operation of the pump in one chamber. is as follows:

The eccentric strap 31 vis given, by means of the eccentric 29, an oscillatory motion with and about the oscillating shaft. 35 and coincidentally swings eccentrically about the drive shaft 27. The ecccentricity of the 'eccentric disc 29 is such that under normal conditions.`

a .point'7 3 (Figs. 143), on the outermost edge of they eecentrlc strap, is in grazing Contact `with the eccentic Wall of the partial cylinder 23, while an oppositely located point on the strap is some distance from the cylinder wall. This arrangement of parts results in a some` what crescentsshaped forcing chamber being formed and likewise a suction chamber, each of which revolves'counter-clockwise about the cylinder wall, the eccentric strap being the forcing member ofthe pump (Fig. 1).`

A seal is formed at the grazing point 73 by g the pumped fluid, such-seal being promoted by the fact that the point 73 and the wall have almost a perfect rolling Contact, when they do make contact, there being only a. slight relaf tive velocity. Should contact take place between the strap 31 and cylinder Wall 23 due to wear of the'eccentric the low relative velocities will decrease the wear.

The suction chamber becomes a forcing chamber as the Vgrazing point 73 passes the lower lip 75 of the intake passage 5 (Figs.'2

and 3). In Fig. 2 the suction chamberhas just become a forcing chamber, the charge having been taken in and being about to be compressed.` The head pressurein the eX- r haust chamber 13 holds the dischargevalve 51 down, its horizontal projected area being great enough to cause a downward seating force. j

In the pump posit-ion referred to (Fig. 2), the charge has been cut oil' from the suction side because the grazing point 73 has passed the lip 75.

As the eccentric moves counter-clockwise the condition` shown in Fig. 1 is met with wherein the crescent-shaped forcing chamber (rearwardly disposed) is becoming smaller as it revolves, thereby compressing and forcing its contents .out` thrQugh the` discharge Cil passage 10, to the discharge chamber 13, the luid having been compressed to such a degree that it has opened the discharge valve to its maximum; that is, the dis charge valve lug 67 has touched its stop 69. --v The dischargevalve 5l under no conditions can cut od the flow to the discharge when the pump is near that part o'fits cycle' slioivii in Fi g. l, because as the stop 7ly prevents the gate 57 from touching the eccentric While the pump is compressing. i j As soonvas the grazing point 7 3 has passed the torivardedge of lthe lower surface G23 on thedischai'ge valve 5l and up to the time said point passes lip'75, the gate 57 on the valve 51 vis pressed down by the discharge head pressure, the suction. chamber beingunder lower pressure. Dui-ing this period vof the cycle the. gate 57 rests on the eccentric strap 3l (Fig. 2), because as the stop 67 is not etiective until the eccentric 29 drops-the strap 31 to a position corresponding to the passage of the grazing point 73 over lip 75. The result of this is'tliat during the time the. compressing cham-v ber is connected with the discharge chamber, the valve is always open and during the time the suction'chambeif couldbe connected to the 'discharge chamber 13' as tar as contiguityl is concerned, the valve is closed, that is, pressed down and in contact with theeccentrie strap,

vcutting oft the return of compressed fluid, and

continues so until the suction chamber becomes a pressure chamber. Y f

Byreason et the above described means the rpump in emptying its. compression chamber,

in etlect, does away with the chamber entirely and the suction eventfis carried on by a dit'- if'ei'ent chamber which in turn becomes av com- This construction reduces trapped in the clearancespace ofthe ordinary reciprocating pump. "Phe present device .ther-'etere has more capacit-y 'tera givenv size.

FigrQ shows a charge of luid just as it has been cut .oli from the .suction side of the pump but notyet compressed, the discharge valve being pressed to its. lowermost positionk by discharge head pressure, Fig.' 2, shows the last pointot contact between the eccentric sti'apfl and the gate 57.

Fig. 3 shows the airangeinentfan instant later when the charge has been slightly compressed, the eccentric .strap having` dropped away iroin the gate 59 of the discharge valve 5l, permitting compressed fluid to flow to the discharge and incidently to open further'V the discharge valve gateby means ot a ivedging action.

Fig. l shows `the suction chamber forming, and drawing in a charge While the compression chamber empties itself.

The valve action in this pump is controlled by the pressures involved and Without cains or other linkage, and no intakevalve is realloiving said iiuidV iuired. i The pump is thus compact, and iiil expensive to construct.

ln view olf the above, it will be seentliat the several objects of the invention are achieved and otheradvantageous results attained,y 1 ,Y Y

' As many changes could be made in carrying out the above constructions Without departing troni thescope of the invention,it is intended that all 'matter contained in the above descrip'- tion-or shoivnin the accompanyingdrawings 'intakeand discharge 'chambers and a cylindaria drive shaft in the cyiinder,an eccentric on the drive yshaitga strap on the eccentricy the stra-p having a clese'iit Within the cylinder whereby rotation et theshatt cainliestl'iev stra p tov i'oice iiuid ahead of the strap and to draiv iluidin behind the strap, .the cylinder having an opening,-a rocker mounted in the casing,

a lint: connecting the roclzeiand strap and serving as seal between the intalie and discharge chambers, and yan oscillating check valve mounted coaxially .with the rocker and forcedagainst the strap by pressure'oiir 'thi-id in the discharge chamber when the grazing point-fot strap against cylinder reaches the' iincomplete portion et the cylinder.

2. A pump con'iprising a casing iiaving intakeand discharge chambers anda cylinder, a drive shaft in the cylinder,` ance-centric on the drive shaft', a strap on the eccentric, the strap Vliaving a close tit Within the cylinder vwhereby rotationo't the shaft causes the strap to torce fluid ahead ot the strap and todraw 'fluid in behind the strap, the cylinder having 'a rocker mounted in the casing,

an opening,

a link connecting the rocker and strapaiid serv 'g as a seal between the intake and discharge chambers,and a check valve forced against the strap by pressure ot fluid in the discharge chamber when the grazing point ot ,strapV against cylinder reaches the incomplete yioition of the cvlinder the valve iittine' the v J 7 1 .u

contour of theL strap as tne grazing point` reaches said incomplete portion oit the cylinder. y n

. 3. Apuinp comprising anca-sing having intake and discharge chambers and a cylinder, a drive shatt inthe cylinder, an eccentric on the drive shaft, a strap on the eccentric, the strap liavinga close fit within the cylinder whereby rotation ofthe shaft causes the strap to lforcei'luidahead of the strap and to draw 'fluid in behind the strap, the cylinder having an opening, a seal between intake vand discharge chambers, and a check valve forced against the strap by pressure of iiuid in the discharge chamber when the grazing point of strap against cylinder reaches the incomplete portion of the cylinder, the valve have ing itsedge nea-rest the cylinder vaway trom` lit) .against the underside of the valve Y take and discharge chambers and a cylinder,

" a drive shaft in the cylinder, an eccentric on the drive shaft, a strap on the eccentric, the strap having a close fit within the cylinder whereby rotation of the shaft causes the Y strap to force fluid. ahead of the strap and to `the grazing `take and discharge chambers and strap having a close t within l the drive shaft, a stra draw fluid in behind the strap, thecylinder having an opening, a rocker mounted in the casing, a link connecting the rocker and strap and' serving as a seal between the intake and discharge chambers, and a check valve forced against the strap by' pressure of-fluid-in the discharge chamber when the grazing point of strap against cylinder reaches the incomplete portion of the cylinder the valve fitting the contour of the strap as the grazing point reaches said incomplete 4portion of the cylinder and having its edge nearest the cylinder away from the strap as whereby the next fluid forced against the :underside of the valve wedges the valve away from the strap, and a stop limiting the travel of the valve in a direction toward the strap.

5. A pump comprising a casinor having ina cylinder, a drive shaft in the cylinder, an eccentric on the drive shaft, a stra on the eccentric, the g the cylinder whereby rotation of the shaft causes the strap to force fluid ahead of the strap and `to draw fluid in behind the strap, the cylinder having an opening, a seal between intakeV and discharge chambers, and an oscillating check valve mounted coaxially with the rocker and forced against the strap by pressure of fluid in the discharge chamber when the grazing point of strap against cylinder reaches the incomplete portion of the cylinder.`

6. A pump comprising a casing having in take and discharge chambers and a cylinder,

a drive shaft in the cylinder, an eccentric on on the eccentric, the strap havinga close t within the cylinder whereby rotation of the shaft causes the strap to force fluid aheadof the strap and to draw fluid in behind the strap, the cylinder having an opening, a rocker mounted in the casing, a link connecting the rocker and strap and serving as a seal between the intake and discharge chambers, a checkva-lve forced against the strap by pressure of fluid in the discharge Chamber when the grazing point of strap point reaches the cylinder again,

against cylinder rea `togfoice fluid ahead of against cylinder reaches theincomplete pori tion of the cylinder, the valve fitting the contour of the strap as the grazing point reaches said incomplete portion of the cylinder and having its edge nearest tlie cylinder away from the strap asl the gra-zingpointreaches the cylinder i again, lwhereby the next fluid forced against the underside ofthe valve wedges the valve away from the strap,

7. A pump comprising a casin having intakeand discharge chambers an a cylinder, a drive shaft in the cylinder, an eccentric on `and a stop limiting the travel of the valve in 'a direction toward the strap. i

`the drive `shaft,`a stra. on theeccentric, the `l t within the cylinder an opening, a rocker mounted in the casing a i link connecting the rockerand strap and servingas a seal between the intake and discharge chambers,

a check valve forced against the strap by pressure offluid in the discharge chamber when the glrazing point of strap c es'the incomplete por tion of the cylinder, the valve fitting the contour of the strap as the grazing point reaches said incomplete portion ofthe cylinderand having its edge nearest the cylinder away from the strap as the .iji-azing-y point reachesV the cylinder again, wherebythe next fluid forced against the `underside of-tlie valve -wedges the valve away'from the strap,iand

stops limiting the travel of the valve in each direction. n i

8. A pump comprisinga casing having intake and discharge chambers and a cylinder, a drive shaft inthe cylinder, an eccentric on 'the drive shaft, a stra strap having a close fig; within the cylinder whereby rotation of the shaft causes the strap fluid in behind the strap, the cylinder having an opening, a. seal between intake and discharge chambers, and a check valve forced against the strap by pressure of fluidin the,

discharge chamber when the grazing point `of, strap against cylinder reaches the incomplete portion of the cylinder, the .valve fitting the contour ofthe strap as the grazing point reaches said incomplete portion of the cyinder', and a stop limiting the travel of the va ve. 1

In testimony whereof, I have `signed my the strap and to draw Y on the eccentric, the

name to this specification this 24th day of i May, 1924.

SHERWOOD HINDS, 

